Lenovo ThinkServer TD350 70DG User Manual And Hardware Maintenance Manual page 175

19. Use a cleaning pad to wipe the thermal grease from the heat sinks and the top of the microprocessors.
Dispose of the cleaning pad after all of the thermal grease is removed.
20. Use one of the following methods to apply appropriate amount of thermal grease to the top of the
microprocessors in the shape of a cross or a circle as shown. Using too much or too little thermal grease
can cause a thermal problem due to imperfect contact with the components.
Notes:
• Do not touch the thermal grease.
• Keep the thermal grease off the system board.
Figure 126. Applying the thermal grease to the top of the microprocessor
21. Install the heat sinks on the new system board. See "Replacing the heat sink" on page 154.
22. The old system board must be returned with two microprocessor socket covers to protect the pins on
the microprocessor sockets during shipping and handling. Use the microprocessor socket covers
removed from the new system board.
To install a microprocessor socket cover on the old system board, do the following:
a. Close the microprocessor retainer. Press down the small handle
inward to secure it. Then, press down the small handle
lock the microprocessor retainer into position.
Note: There are two marks on the microprocessor retainer. Ensure that you close the small handle
marked with first and then close the other small handle marked with
sequence when you close the small handles.
Figure 127. Securing the microprocessor retainer
1 first and then push the handle
2 and then push the handle inward to
. Always follow the correct
.
Chapter 6 Replacing hardware
161